features/locks: implement fgetxattr and fsetxattr

implement xattrs for GF_XATTR_LOCKINFO_KEY, which will be used
for posix-locks migration from old to new graph after a switch.

fgetxattr (fd, GF_XATTR_LOCKINFO_KEY) will return a dict.
This dict has a serialized dict stored for key
GF_XATTR_LOCKINFO_KEY. This serialized dict in turn has fdnum
value of locks acquired on this fd with modified pathinfo
(containing hostname and base directory components) as key.

fsetxattr (newfd, GF_XATTR_LOCKINFO_KEY, dict) has following
semantics. dict can be the result of a previous fgetxattr with
GF_XATTR_LOCKINFO_KEY. In that case, a dict_get on dict
constructed using serialized buffer is done on modified pathinfo
as key. If a value is got, that value is treated as fdnum and for
every lock l on newfd->inode we do,
      if (l->fdnum == fdnum) {
         l->fdnum = fd_fdnum (newfd);
         l->transport = <connection identifier of connection on which fsetxattr came>;
      }

Signed-off-by: Raghavendra G <raghavendra@gluster.com>
Change-Id: I73a8f43aa0b6077bc19f8de52205ba748f2d8bbe
BUG: 808400
Reviewed-on: http://review.gluster.org/4120
Reviewed-by: Vijay Bellur <vbellur@redhat.com>
Tested-by: Vijay Bellur <vbellur@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/xlators/features/locks/src/locks.h b/xlators/features/locks/src/locks.h
index d2b47bffed7..7ffc67e1b88 100644
--- a/xlators/features/locks/src/locks.h
+++ b/xlators/features/locks/src/locks.h
@@ -149,6 +149,7 @@ typedef struct __pl_fd pl_fd_t;
 typedef struct {
         gf_boolean_t    mandatory;      /* if mandatory locking is enabled */
         gf_boolean_t    trace;          /* trace lock requests in and out */
+        char           *brickname;
 } posix_locks_private_t;
 
 typedef struct {